essentially, all spyders are the same in how they work. Spyders are simple markers to take apart and clean. The MR4 is just a military style marker and has an EKO valve that helps efficiency and has a single trigger frame so it wont be the fastest shooting marker out there. As far as distance most markers will be about the same, what will help is a good paint to barrel bore ratio. The length of the barrel doesnt make that much of difference and is more of a preference. The longer the barrel, the easier it will be to shoot through some brush but it can be that much more of a chore to get around.